odr - Optimal Design and Statistical Power for Experimental Studies
Investigating Main, Mediation, and Moderation Effects
Calculate the optimal sample size allocation that uses the
minimum resources to achieve targeted statistical power in
experiments. Perform power analyses with and without
accommodating costs and budget. The designs cover single-level
and multilevel experiments detecting main, mediation, and
moderation effects (and some combinations). The references for
the proposed methods include: (1) Shen, Z., & Kelcey, B.
(2020). Optimal sample allocation under unequal costs in
cluster-randomized trials. Journal of Educational and
Behavioral Statistics, 45(4): 446-474.
<doi:10.3102/1076998620912418>. (2) Shen, Z., & Kelcey, B.
(2022b). Optimal sample allocation for three-level multisite
cluster-randomized trials. Journal of Research on Educational
Effectiveness, 15 (1), 130-150.
<doi:10.1080/19345747.2021.1953200>. (3) Shen, Z., & Kelcey, B.
(2022a). Optimal sample allocation in multisite randomized
trials. The Journal of Experimental Education, 90(3), 693-711.
<doi:10.1080/00220973.2020.1830361>. (4) Shen, Z., Leite, W.,
Zhang, H., Quan, J., & Kuang, H. (2025). Using ant colony
optimization to identify optimal sample allocations in
cluster-randomized trials. The Journal of Experimental
Education, 93(1), 167-185. <doi:10.1080/00220973.2024.2306392>.
(5) Shen, Z., Li, W., & Leite, W. (in press). Statistical power
and optimal design for randomized controlled trials
investigating mediation effects. Psychological Methods.
<doi:10.1037/met0000698>. (6) Champely, S. (2020). pwr: Basic
functions for power analysis (Version 1.3-0) [Software].
Available from <https://CRAN.R-project.org/package=pwr>.
